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| United States Patent |
5,318,931
|
|
Nakaguchi
, et al.
|
June 7, 1994
|
Glass panes for vehicles
Abstract
Glass for vehicles comprising from 65 to 80% by weight of SiO.sub.2, from 0
to 5% by weight of Al.sub.2 O.sub.3, from 0 to 5% by weight B.sub.2
O.sub.3, from 0 to 10% by weight of MgO, from 5 to 15% by weight of CaO,
from 10 to 18% by weight of Na.sub.2 O, from 0 to 5% by weight of K.sub.2
O, from 5 to 15% by weight in total of MgO and CaO, from 10 to 20% by
weight in total of Na.sub.2 O and K.sub.2 O, from 0.1 to 1% by weight of
cerium oxide in terms of CeO.sub.2, from 0.2 to 0.6% by weight of iron
oxide in terms of Fe.sub.2 O.sub.3, from 0 to 0.005% by weight of CoO,
from 0 to 0.01% by weight of NiO, and from 0.0005 to 0.005% by weight of
Se, and glass for vehicles comprising from 65 to 80% by weight of
SiO.sub.2, from 0 to 5% by weight of Al.sub.2 O.sub.3, from 0 to 5% by
weight of B.sub.2 O.sub.3, from to 10% by weight of MgO, from 5 to 15% by
weight of CaO, from 10 to 18% by weight of Na.sub.2 O, from 0 to 5% by
weight of K.sub.2 O, from 5 to 15% by weight in total of MgO and CaO, from
10 to 18% by weight in total of Na.sub.2 O and K.sub.2 O, from 0.1 to 1%
by weight of cerium oxide in terms of CeO.sub.2, from 0 to 1% by weight of
TiO.sub.2, from 0.2 to 0.6% by weight of iron oxide in terms of Fe.sub.2
O.sub.3, from 0 to 0.005% by weight of CoO, from 0 to 0.01% by weight of
NiO, and from 0.0005 to 0.005% by weight of Se. The glass is gray-tinted
while exhibiting excellent ultraviolet and heat absorption.
| Inventors:
|
Nakaguchi; Kunio (Osaka, JP);
Toshikiyo; Yoshikazu (Osaka, JP);
Sunada; Takashi (Osaka, JP)
|
| Assignee:
|
Nippon Sheet Glass Co., Ltd. (Osaka, JP)
|
| Appl. No.:
|
832582 |
| Filed:
|
February 7, 1992 |
Foreign Application Priority Data
| Current U.S. Class: |
501/64; 501/27; 501/55; 501/66; 501/68; 501/69; 501/70; 501/71; 501/904; 501/905 |
| Intern'l Class: |
C03C 004/08 |
| Field of Search: |
501/27,55,64,66,68,69,70,71,904,905
|
References Cited
U.S. Patent Documents
| 2860059 | Nov., 1958 | Molter et al.
| |
| 3296004 | Jan., 1967 | Duncan | 501/71.
|
| 3300323 | Jan., 1967 | Plumat et al. | 501/71.
|
| 3723142 | Mar., 1973 | Kato et al. | 501/71.
|
| 4101705 | Jul., 1978 | Fischer et al. | 428/220.
|
| 4104076 | Aug., 1978 | Pons | 501/71.
|
| 4792536 | Dec., 1988 | Pecoraro et al. | 501/70.
|
| 4866010 | Sep., 1989 | Boulos et al. | 501/71.
|
| Foreign Patent Documents |
| 0297404 | Jan., 1989 | EP.
| |
| 2074983 | Oct., 1971 | FR.
| |
| 2071082 | Sep., 1981 | GB.
| |
| 2252973 | Aug., 1992 | GB.
| |
Primary Examiner: Green; Anthony
Assistant Examiner: Marcheschi; Michael
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak & Seas
Claims
What is claimed is:
1. Glass for vehicles consisting essentially of:
from 65 to 80% by weight of SiO.sub.2 ;
from 0 to 5% by weight of Al.sub.2 O.sub.3 ;
from 0 to 5% by weight of B.sub.2 O.sub.3 ;
from 0 to 10% by weight of MgO;
from 5 to 15% by weight of CaO;
from 10 to 18% by weight of Na.sub.2 O;
from 0 to 5% by K.sub.2 O;
from 5 to 15% by weight in total of MgO and CaO;
from 10 to 20% by weight in total of Na.sub.2 O and K.sub.2 O;
from 0.1 to 1% by weight of cerium oxide in terms of CeO.sub.2 ;
from 0.2 to 0.6% by weight of iron oxide in terms of Fe.sub.2 O.sub.3,
wherein iron oxide includes both FeO and Fe.sub.2 O.sub.3 ;
0% by weight of CoO;
0% by weight of NiO; and
from 0.0005 to 0.005% by weight of Se,
wherein said glass has an excitation purity P.sub.e of 7.6% or more.
2. Glass for vehicles as claimed in claim 1, wherein the proportion of FeO
is from 23 to 35% by weight based on the total iron oxide.
3. Glass for vehicles as claimed in claim 1, wherein the glass with a
thickness of 4 mm has a visible light transmission of at least 70% with
the CIE standard illuminant A and a dominant wavelength of 570 nm or
longer with the CIE standard illuminant C.
4. Glass for vehicles as claimed in claim 3, wherein the glass with a
thickness of 4 mm has a solar radiation transmission of not more than 60%
and a light transmission of not more than 10% at a wavelength of 350 nm.
5. Glass for vehicles consisting essentially of:
from 65 to 80% by weight of SiO.sub.2 ;
from 0 to 5% by weight of Al.sub.2 O.sub.3 ;
from 0 to 5% by weight of B.sub.2 O.sub.3 ;
from 0 to 10% by weight of MgO;
from 5 to 15% by weight of CaO;
from 10 to 18% by weight of Na.sub.2 O;
from 0 to 5% by K.sub.2 O;
from 5 to 15% by weight in total of MgO and CaO;
from 10 to 18% by weight in total of Na.sub.2 O and K.sub.2 O;
from 0.1 to 1% by weight of cerium oxide in terms of CeO.sub.2 ;
from 0 to 1% by weight of TiO.sub.2 ;
from 0.2 to 0.6% by weight of iron oxide in terms of Fe.sub.2 O.sub.3,
wherein iron oxide includes both FeO and Fe.sub.2 O.sub.3 ;
0% by weight of CoO;
0% by weight of NiO; and
from 0.0005 to 0.005% by weight of Se,
wherein said glass has an excitation purity P.sub.e of 7.6% or more.
6. Glass for vehicles as claimed in claim 5, wherein the proportion of FeO
is from 23 to 35% by weight based on the total iron oxide.
7. Glass for vehicles as claimed in claim 5, wherein the glass with a
thickness of 4 mm has a visible light transmission of at least 70% with
the CIE standard illuminant A and a dominant wavelength of 570 nm or
longer with the CIE standard illuminant C.
8. Glass for vehicles as claimed in claim 7, wherein the glass with a
thickness of 4 mm has a solar radiation transmission of not more than 60%
and a light transmission of not more than 10% at a wavelength of 350 nm.
Description
FIELD OF THE INVENTION
The present invention relates to glass (pane) for vehicles, particularly
automobiles. More particularly, it relates to gray-tinted glass for
vehicles excellent in ultraviolet and heat ray absorption.
BACKGROUND OF THE INVENTION
Colored glass which has been used as window glass of vehicles includes
blue-tinted glass containing Fe.sub.2 O.sub.3 doped with CoO, green-tinted
glass having a higher Fe.sub.2 O.sub.3 content than blue-tinted glass to
have improved heat ray absorption, and gray-tinted or bronzed glass
containing Fe.sub.2 O.sub.3, CoO, NiO, and Se as colorants.
While blue-tinted and green-tinted glass having a relatively high Fe.sub.2
O.sub.3 content has relatively high heat and ultraviolet absorbing power,
there still is an eagerness to protect interior trim from deterioration
due to ultraviolet light with the recent trend to luxurious trim of
automobiles. To cope with this demand, glass having high ultraviolet
absorbing power while satisfying the requirements for energy saving has
recently been developed. Having a higher Fe.sub.2 O.sub.3 content than in
conventional glass, this glass is also tinted in green.
On the other hand, gray-tinted or bronzed glass has been desired from
considerations of designs of vehicles. However, having a lower Fe.sub.2
O.sub.3 content than in blue-tinted glass, conventional gray-tinted or
bronzed glass has insufficient ultraviolet and heat absorption for
satisfying the eagerness to protect interior trim from ultraviolet
deterioration. It has therefore been demanded to develop grain-tinted or
bronzed glass having high ultraviolet and heat ray absorbing power.
The present inventors previously proposed gray heat-absorbing glass
containing tin oxide as a reducing agent and thereby having a high heat
ray absorption, but this glass is costly because tin oxide is expensive.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above-mentioned problems
confronting the conventional glass for vehicles and to provide gray glass
which has high ultraviolet and heat ray absorbing power and is suitable
for use in vehicles.
Other objects and effects of the present invention will apparent from the
following description.
The prevent invention relates to glass for vehicles comprising from 65 to
80% by weight of SiO.sub.2, from 0 to 5% by weight of Al.sub.2 O.sub.3,
from 0 to 5% by weight of B.sub.2 O.sub.3, from 0 to 10% by weight of MgO,
from 5 to 15% by weight of CaO, from 10 to 18% by weight of Na.sub.2 O,
from 0 to 5% by weight of K.sub.2 O, from 5 to 15% by weight in total of
MgO and CaO, from 10 to 20% by weight in total of Na.sub.2 O and K.sub.2
O, from 0.1 to 1% by weight of cerium oxide in terms of CeO.sub.2, from
0.2 to 0.6% by weight of iron oxide in terms of Fe.sub.2 O.sub.3 (total
content of iron oxide calculated as Fe.sub.2 O.sub.3), from 0 to 0.005% by
weight of CoO, from 0 to 0.01% by weight of NiO, and from 0.0005 to 0.005%
by weight of Se.
The prevent invention also relates to glass for vehicles comprising from 65
to 80% by weight of SiO.sub.2, from 0 to 5% by weight of Al.sub.2 O.sub.3,
from 0 to 5% by weight of B.sub.2 O.sub.3, from 0 to 10% by weight of MgO,
from 5 to 15% by weight of CaO, from 10 to 18% by weight of Na.sub.2 O,
from 0 to 5% by weight of K.sub.2 O, from 5 to 15% by weight in total of
MgO and CaO, from 10 to 18% by weight in total of Na.sub.2 O and K.sub.2
O, from 0.1 to 1% by weight of cerium oxide in terms of CeO.sub.2, from 0
to 1% by weight of TiO.sub.2, from 0.2 to 0.6% by width of iron oxide in
terms of Fe.sub.2 O.sub.3 (total content of iron oxide calculated as
Fe.sub.2 O.sub.3), from 0 to 0.005% by weight of CoO, from 0 to 0.01% by
weight of NiO, and from 0.0005 to 0.005% by weight of Se.
DETAILED DESCRIPTION OF THE INVENTION
The glass for vehicles of the present invention preferably has, with a
thickness of 4 mm, a visible light transmission of at least 70% with the
CIE standard illuminant A, and a dominant wavelength of 570 nm or longer,
particularly from 573 to 580 nm, with the CIE standard illuminant C.
The glass for vehicles of the present invention more preferably has, with a
thickness of 4 mm, a solar radiation transmission of not more than 60%,
particularly not more than 58%, a light transmission of not more than 10%
at a wavelength of 350 nm, and an excitation purity of not more than 15%
with the CIE standard illuminant C.
Concerning the contents of the components in the glass, the term "%" used
hereinafter is % by weight.
SiO.sub.2 is a basic ingredient of glass. If its content is less than 65%,
the glass has reduced durability. If it exceeds 80%, the composition is
difficult to melt. The content of SiO.sub.2 is preferably from 68 to 73%.
Al.sub.2 O.sub.3 serves to improve durability of glass. If its content
exceeds 5%, the composition is difficult to melt. A preferred Al.sub.2
O.sub.3 content is from 0.1 to 2%, and more preferably from 0.5 to 2%.
B.sub.2 O.sub.3 is used, while not essential, for improvement of durability
of glass and also as a melting aid. The upper limit of its content is 5%.
B.sub.2 O.sub.3 of higher content interferes with production of flat glass
due to volatilization, etc. The content of B.sub.2 O.sub.3 is preferably
from 0 to 1%.
MgO and CaO both serve to improve durability of glass and to control
liquidus temperature and viscosity at the time of glass forming. If the
MgO content exceeds 10%, the liquidus temperature becomes high. If the CaO
content is less than 5% or higher than 15%, the liquidus temperature
becomes high. The contents of MgO and CaO are preferably from 1 to 6% and
from 6 to 12%, respectively. If the total content of MgO and CaO is less
than 5%, the resulting glass has deteriorated durability. If it exceeds
15%, the liquidus temperature becomes high. The total content of MgO and
CaO is preferably from 8 to 14%.
Na.sub.2 O and K.sub.2 O are used as a glass melting accelerator. If the
Na.sub.2 O content is less than 10%, or if the total content of Na.sub.2 O
and K.sub.2 O is less than 10%, the effect of accelerating melting is
weak. If Na.sub.2 O content exceeds 18%, or if the total content of
Na.sub.2 O and K.sub.2 O exceeds 20%, durability is reduced. Since K.sub.2
O is more expensive than Na.sub.2 O, it is used in an amount of 5% at
most. The contents of Na.sub.2 O and K.sub.2 O are preferably from 11 to
15% and from 0 to 2%, respectively, and the total content of Na.sub.2 O
and K.sub.2 O is preferably from 11 to 16%.
Cerium oxide in glass includes CeO.sub.2 and Ce.sub.2 O.sub.3, both of
which exhibit ultraviolet absorbing power. If the cerium oxide content in
terms of CeO.sub.2 content is less than 0.1%, the ultraviolet absorbing
effect is weak. If it exceeds 1%, the glass absorbs visible light to
reduce the visible light transmission. The content of the cerium oxide is
preferably from 0.3 to 1%.
TiO.sub.2 is used, while not essential, as an ultraviolet absorber. If iron
oxide coexists with TiO.sub.2, the ultraviolet absorbing power is enhanced
by the interaction between iron oxide and TiO.sub.2. The amount of cerium
oxide which is expensive, can be reduced by incorporating TiO.sub.2, and
thus the use of TiO.sub.2 is also preferred in view of the production
cost. If its content is more than 1% and iron oxide coexists, the glass
absorbs the short wavelength region of visible light to reduce the visible
light transmission.
Iron oxide in glass includes Fe.sub.2 O.sub.3 and FeO. The former absorbs
ultraviolet rays, and the latter absorbs heat rays. If the iron oxide
content in terms of Fe.sub.2 O.sub.3 content (total iron oxide content
calculated as Fe.sub.2 O.sub.3) is less than 0.2%, the effects of
absorbing ultraviolet and heat rays are small. If it exceeds 0.6%, the
visible light transmission is unfavorably reduced. The content of the iron
oxide is preferably from 0.3 to 0.6%
The proportion of FeO is preferably from 23 to 35% by weight based on the
total iron oxide. If the proportion of FeO is too large, the glass tends
to be of reductive nature and difficult to be colored with selenium
although the absorbing power of heat rays becomes large.
The content of FeO in the glass ([FeO] % by weight) is obtained from the
following equation:
[FeO]=-0.25635.times.Log.sub.10 (T.sub.1000 /100)-0.008
wherein T.sub.1000 % represents the light transmission at a wavelength of
1,000 nm of the glass. The proportion of FeO (R % by weight) based on the
total iron oxide is obtained from the following equation:
R=111.13.times.([FeO]/[T-Fe.sub.2 O.sub.3 ])
wherein [T-Fe.sub.2 O.sub.3 ] % by weight represents the total iron oxide
content in terms of Fe.sub.2 O.sub.3 of the glass.
CoO has an absorption peak at around 600 nm and is therefore used for fine
adjustment of the dominant wavelength of glass. If its content exceeds
0.005%, the visible light transmission is reduced.
NiO has an absorption peak at around 450 nm and is also used for fine
adjustment of the dominant wavelength of glass. If its content exceeds
0.01%, the visible light transmission is reduced.
Both CoO and NiO function to reduce the visible light transmission and do
not contribute to absorption of ultraviolet and heat rays. For the reason,
it is preferred not to add these components.
Se is an essential component for neutralizing the green color of iron
oxide-containing glass to thereby provide gray glass. If its content is
less than 0.0005%, the color neutralizing effect is insubstantial. If it
exceeds 0.005%, the visible light transmission of the resulting glass is
unfavorably reduced. The content of Se is preferably from 0.0005 to
0.002%.
If desired, the glass according to the present invention may further
contain the following optional components in addition to the
above-mentioned components as long as the effects of the present invention
are not impaired. That is, the glass may contain BaO, ZnO, TiO.sub.2, or
ZrO.sub.2 in an amount of up to 1% by weight for the purpose of improving
durability. The glass may also contain Li.sub.2 O or F as a melting aid in
an amount of up to 1% by weight. Further, the glass may contain SO.sub.3,
As.sub.2 O.sub.3, Sb.sub.2 O.sub.3, or Cl as a fining agent in an amount
of up to 1% by weight.
The present invention is now illustrated in greater detail by way of
Examples and Comparative Example, but is not construed as being limited
thereto. All parts, percents and the like are by weight unless otherwise
indicated.
EXAMPLES 1 TO 23 AND COMPARATIVE EXAMPLE 1
Glass samples having the compositions shown in Tables 1 to 3 below were
prepared as follows.
Silica sand, borax, feldspar, limestone, dolomite, soda ash, salt cake,
carbon, titanium oxide, cerium oxide, red iron oxide, cobalt oxide, nickel
oxide, and selenium were compounded according to the compositions of
Tables 1 to 3, and the resulting batch was heat-melted in an electric
furnace. The molten glass was cast and slowly cooled to room temperature.
The cooled color glass was cut and polished to prepare a 4 mm thick
specimen for determination of optical characteristics with a
self-recording spectrophotometer Model 330, manufactured by Hitachi, Ltd.
Optical characteristics of each of the resulting specimen and, for
comparison, bronzed glass conventionally employed for vehicles were
determined at a view angle of 2.degree. using the CIE standard illuminants
A and C. The results obtained are shown in Tables 1 to 3.
TABLE 1
__________________________________________________________________________
Example
Example
Example
Example
Example
Example
Example
Example
1 2 3 4 5 6 7 8
__________________________________________________________________________
Composition:
SiO.sub.2 71.08
71.27
70.26
71.27
71.27
71.18
70.68
71.45
B.sub.2 O.sub.3
0 0 1.00 0 0 0 0.50 0
Al.sub.2 O.sub.3
1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50
MgO 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00
CaO 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00
Na.sub.2 O 13.50
13.50
13.50
13.50
13.50
13.50
13.50
13.50
K.sub.2 O 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
CeO.sub.2 0.50 0.40 0.40 0.40 0.40 0.45 0.45 0.30
TiO.sub.2 0 0 0 0 0 0 0 0
[T-Fe.sub.2 O.sub.3 ].sup.1)
0.42 0.33 0.33 0.33 0.33 0.37 0.37 0.25
Fe.sub.2 O.sub.3
0.298
0.236
0.233
0.241
0.236
0.262
0.264
0.178
FeO 0.110
0.085
0.087
0.080
0.085
0.097
0.095
0.065
R.sup.2) 29.1 28.5 29.3 27.1 28.5 29.2 28.4 29.0
CoO 0 0 0 0.0005
0.0010
0 0 0
NiO 0 0 0.0050
0 0 0 0 0
Se 0.0013
0.0015
0.0010
0.0010
0.0008
0.0013
0.0010
0.0017
Optical Characteristics:
T.sub.G .sup.3) (%)
55.4 59.3 60.0 60.0 61.0 57.5 58.6 64.1
Y.sub.A .sup.4) (%)
70.3 70.3 71.6 71.4 73.0 70.9 73.3 70.7
.lambda..sub.d .sup.5) (nm)
575 578 575 574 571 576 574 580
P.sub.e .sup.6) (%)
9.6 11.4 9.6 5.9 4.4 9.8 7.6 12.7
T.sub.UV .sup.7) (%)
5.6 8.1 9.8 9.8 10.5 6.9 7.8 12.0
__________________________________________________________________________
Note:
.sup.1) [T-Fe.sub.2 O.sub.3 ]: Total content of iron oxide in terms of
Fe.sub.2 O.sub.3
.sup.2) R: Proportion of FeO in the total iron oxide
.sup.3) T.sub.G : Solar radiation transmission, measured according to JIS
R3208
.sup.4) Y.sub.A : Visible light transmission (illuminant A), measured
according to JIS Z8722
.sup.5) .lambda..sub.d : Dominant wavelength (illuminant C), measured
according to JIS Z8722
.sup.6) P.sub.e : Excitation purity (illuminant C)
.sup.7) T.sub.UV : Ultraviolet transmission at 350 nm
TABLE 2
__________________________________________________________________________
Example
Example
Example
Example
Example
Example
Comparative
9 10 11 12 13 14 Example 1
__________________________________________________________________________
Composition:
SiO.sub.2 71.44
70.58
70.58
70.83
70.83
70.07
71.25
B.sub.2 O.sub.3
0 0 0 0 0 0 0
Al.sub.2 O.sub.3
1.50 1.50 1.50 1.50 1.50 1.50 1.52
MgO 4.00 4.00 4.00 4.00 4.00 4.00 3.85
CaO 8.00 8.00 8.00 8.00 8.00 8.00 8.92
Na.sub.2 O 13.50
13.50
13.50
13.50
13.50
13.50
13.31
K.sub.2 O 1.00 1.00 1.00 1.00 1.00 1.00 0.90
CeO.sub.2 0.30 1.00 1.00 0.75 0.75 0.75 0
TiO.sub.2 0 0 0 0 0 0 0
[T-Fe.sub.2 O.sub.3 ].sup.1)
0.25 0.42 0.42 0.42 0.42 0.60 0.24
Fe.sub.2 O.sub.3
0.178
0.282
0.307
0.298
0.306
0.425
0.184
FeO 0.065
0.124
0.101
0.110
0.103
0.157
0.050
R.sup.2) 29.0 32.8 26.7 29.1 27.3 29.1 23.2
CoO 0.0010
0 0 0 0 0 0.0007
NiO 0.0050
0 0 0 0 0 0.0035
Se 0.0010
0.0013
0.0013
0.0013
0.0013
0.0018
0.0006
Optical Characteristics:
T.sub.G .sup.3) (%)
63.9 54.5 57.3 55.8 56.7 44.1 69.0
Y.sub.A .sup.4) (%)
70.8 70.1 70.5 70.3 70.1 62.2 77.0
.lambda..sub.d .sup.5) (nm)
576 576 577 576 577 575 576
P.sub.e .sup.6) (%)
7.9 9.6 10.8 9.8 10.4 13.5 5.0
T.sub.UV .sup.7) (%)
15.6 1.8 0.9 1.7 0.9 1.4 47.7
__________________________________________________________________________
Note:
.sup.1) [T-Fe.sub.2 O.sub.3 ]: Total content of iron oxide in terms of
Fe.sub.2 O.sub.3
.sup.2) R: Proportion of FeO in the total iron oxide
.sup.3) T.sub.G : Solar radiation transmission, measured according to JIS
R3208
.sup.4) Y.sub.A : Visible light transmission (illuminant A), measured
according to JIS Z8722
.sup.5) .lambda..sub.d : Dominant wavelength (illuminant C), measured
accordingj to JIS Z8722
.sup.6) P.sub.e : Excitation purity (illuminant C)
.sup.7) T.sub.UV : Ultraviolet transmission at 350 nm
TABLE 3
__________________________________________________________________________
Example
Example
Example
Example
Example
Example
Example
Example
Example
15 16 17 18 19 20 21 22 23
__________________________________________________________________________
Composition (% by weight):
SiO.sub.2 71.28
71.17 69.73
70.65 70.45
71.34 71.34
70.90 70.76
B.sub.2 O.sub.3
0 0 1.00 0 0.5 0 0 0 0
Al.sub.2 O.sub.3
1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50
MgO 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00
CaO 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00
Na.sub.2 O 13.50
13.50 13.50
13.50 13.50
13.50 13.50
13.50 13.50
K.sub.2 O 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
CeO.sub.2 0.27 0.18 0.60 0.80 0.20 0.14 0.16 0.40 0.26
TiO.sub.2 0.11 0.25 0.25 0.10 0.50 0.20 0.18 0.17 0.38
[T-Fe.sub.2 O.sub.3 ].sup.1)
0.340
0.400 0.420
0.450 0.350
0.320 0.32 0.53 0.60
Fe.sub.2 O.sub.3
0.250
0.298 0.302
0.334 0.259
0.240 0.240
0.364 0.450
FeO 0.096
0.087 0.106
0.104 0.082
0.072 0.072
0.149 0.135
R.sup.2) 31.4 24.2 28.0 25.7 26.0 25.0 25.0 31.2 25.0
CoO 0 0 0 0 0 0.0008
0 0 0
NiO 0 0 0 0 0 0 0.005
0 0
Se 0.0013
0.0013
0.0013
0.0010
0.0010
0.0015
0.0015
0.0018
0.0015
Optical Characteristics:
T.sub.G .sup.3) (%)
55.9 56.4 56.1 56.4 59.1 57.0 56.4 45.2 45.3
Y.sub.A .sup.4) (%)
70.0 70.1 70.0 70.2 70.0 67.4 67.0 62.3 62.0
.lambda..sub.d .sup.5) (nm)
575 576 575 576 575 577 577 575 575
P.sub.e .sup.6) (%)
10.3 11.5 12.9 11.3 10.1 10.4 13.7 14.1 15.9
T.sub.UV .sup.7) (%)
7.3 8.7 1.8 1.6 2.7 8.5 8.5 2.3 2.8
__________________________________________________________________________
Note:
.sup.1) [T-Fe.sub.2 O.sub.3 ]: Total content of iron oxide in terms of
Fe.sub.2 O.sub.3
.sup.2) R: Proportion of FeO in the total iron oxide
.sup.3) T.sub.G : Solar radiation transmission, measured according to JIS
R3208
.sup.4) Y.sub.A : Visible light transmission (illuminant A), measured
according to JIS Z8722
.sup.5) .lambda..sub.d : Dominant wavelength (illuminant C), measured
accordingj to JIS Z8722
.sup.6) P.sub.e : Excitation purity (illuminant C)
.sup.7) T.sub.UV : Ultraviolet transmission at 350 nm
It can be seen from the results in Tables 1 to 3 that the glass according
to the present invention is gray-tinted while having a high visible light
transmission, a low solar radiation transmission, and a high ultraviolet
absorption. Thus, the glass of the present invention is suitable for use
in not only vehicles but also buildings. While the invention has been
described in detail and with reference to specific examples thereof, it
will be apparent to one skilled in the art that various changes and
modifications can be made therein without departing from the spirit and
scope thereof.
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